1. Field of the Invention
The invention relates to a window system having a novel locking device. In particular, the invention relates to a double-hung type window that has a locking device disposed along both sides of each of the sashes. The locking device prevents the sashes from bending away from the window frame and prevents infiltration of air through the gap between the sash and frame.
2. The Prior Art
Traditional double-hung windows consist of a window frame and two sashes, which slide up and down within grooves on the frame. Many of these windows can also be tilted inward, for ease of cleaning. Since these tiltable windows are only connected to the frame at bottom and top portions, a gap can form between the sides of the sash and the sides of the frame, through which air can infiltrate. This is especially true during high winds, when the wind can bend the sashes inward and increase the size of the gap.
It is therefore an object of the invention to provide a double hung window that can be easily tilted for cleaning, but does not let air infiltrate through the sides of the sashes.
It is another object of the invention to provide a window system that is simple to manufacture and operate.
These and other objects of the invention are provided by a window system comprising a frame having a top, a bottom and two sides, at least one slidable and tiltable sash disposed within the frame, and a locking device attached to each side of the sash. The locking device is pivotable between an unlocked position to permit tilting of the sash, and a locked position which locks the sash to the frame. In the locked position, the locking device prevents any air from infiltrating between the sides of the sash and the frame.
The frame has an elongated recess extending along each side. The locking device comprises an elongated flange having one end connected along the entire side of the sash. The other end of the flange is free and pivots outward in the locked position to fit within the recess of the frame, to prevent any air from infiltrating between the sash and frame. The locking device is held in a locked position by at least one spring connected to the sash and locking device. The spring pushes the locking device outwards, so it naturally rests in the locked position. The spring can be any type of spring, such as a leaf spring, coil spring or wire spring, but a coil spring is preferred. Alternatively, foam or other compressible material could also be used.
There is a latch on a top part of each sash, for allowing the sash to tilt within the frame. The latch has a locked and unlocked position, so that in the locked position the sash is prevented from tilting within the frame and in the unlocked position, the sash may tilt. The locking device is connected to the latch via a connecting device such as a screw, so that when the latch is moved into the locked position, the locking device is also moved into the locked position, and when the latch is unlocked, the locking device is unlocked as well. Thus, no additional efforts are required by the user to activate the locking device apart from the latch. As an alternative to the screw, a pin or wire or any other suitable connecting device may also be used.
To prevent the locking device from pivoting too far outward, there is a protrusion on the free end of the locking device, and a stop on the sash, so that when the locking device pivots into the locked position, the protrusion contacts the stop and prevents over-pivoting of the locking device.
The locking device is preferably made of aluminum, but other materials could also be used. The locking device can be used on a variety of different windows: double hung, single hung and sliding windows. With double hung windows, the locking device runs vertically along the sides of the window. With a sliding window, the locking device runs horizontally along the top and bottom sides of the window.